1. Field of the Invention
The present invention relates to a contact terminal, and more particularly to a contact terminal having a foothold arrangement which can properly interlock with a via of a printed circuit board. The present invention also relates to a connector using the same.
2. Description of Prior Art
Land grid array (LGA) sockets are widely used in various electrical devices to establish electrical connection between a land grid array package and a circuit substrate. Basically, a land grid array socket includes an insulative housing defining a number of passageways and a number of conductive terminals resided in corresponding passageways, respectively. Each conductive terminal includes a resilient arm sticking out of the housing to mate with a grid array package. In use, under compression of the land grid array package, the resilient arm is deflected from its natural position and elastically abuts against the land grid array package thereby forming electrical engagement between the land grid array package and the conductive terminal.
U.S. Pat. No. 6,921,271 issued to Liao, et al. on Jul. 26, 2005 discloses a socket, for electrically connecting a package and a printed circuit board, including a dielectric housing and a plurality of conductive terminals secured in the housing. The housing defines upper and lower surfaces and a number of cells. Each terminal has a retention body secured in a corresponding cell defined on the housing. The retention body has an upper end projecting beyond the upper mating surface and a lower end projecting beyond the lower surface. Upper and lower protrusions extend from the upper and lower mating surfaces of the housing respectively, for supporting the package and abutting against the printed circuit board, respectively.
However, in the existing so called LGA contact terminal, the tail portion of each contact terminal is disposed between an upper surface of the printed circuit board, and a bottom surface of a socket connector. As a result, there is always a gab therebetween such that it is unlikely to reduce the overall height of the socket. On the other hand, in order to have the contact terminal be securely secured within the socket, each contact terminal has to have a certain holdup within the socket such that the thickness of the socket has to be remained to a certain range. If the socket is too thin, then its housing could be broken apart when the contact terminal is inserted. Accordingly, it would be preferably to keep the socket within the certain range, while its overall height can be reduced.
Hence, an improved electrical contact for being used in an electrical connector is required to overcome the disadvantages of the prior art.